Being A Coffee Nerd Taught Me Something About Brewing

Usually it's the other way around. The silly amount of random brewing knowledge I've built up tends to inform a lot of the food science and chemistry stuff I think about.

But this week I was making the first starters of the season for a Scottish 80/- which Square Kegs (my homebrew club) is brewing this weekend for an awesome event called Beerfly Alleyfight put on by Haymarket Brewery. It's part of Chicago's Craft Beer Week and is a simply phenomenal event. But I digress.

We've been making pour-over coffee at my office in a Chemex for a while now. (If you haven't been bit by the coffee bug, you might not want to read on. It's the preferred brewing method of hipsters and snooty coffee snobs.) The standard Chemex rig consists of a burr grinder, the chemex and a scale on which to both weigh out your beans and then for weighing out the hot water.

The important part here is that the Chemex looks a lot like an Erlenmeyer flask and it sits on a gram scale throughout the whole brew process.

For some reason it never occurred to me to use the same scale I use to measure my DME for starters to measure the water. I'd just measure up to what looked like about the right volume based on the markings on the flask. But now that I'm in the habit of using the Chemex, I used the scale for measuring the water. I feel like a moron for never having done that before. (It's dead simple to convert between the two. 1mL = 1 gram of water.)

It just goes to show that you can always draw inspiration from other places in your life.

I Don't Believe In New Year's Resolutions

... but this year I'm making some brewing resolutions for the 2014 season. Jeremy and I are good brewers. We win medals in competition. We can generally turn out consistent beers from batch to batch. The number of hours I've devoted and the amount of educational material I've devoured keep mounting.

But we're still not great. We don't often take a category gold, and we've never won a best in show. Hop character is still hit or miss in our beers. The occasional batch is a clunker and I'll dump it or pawn it off on unsuspecting friends during one of our "family" dinners.

And so, I want to get better. So over the winter I've ruminated on and off about our process and what we can change for the positive. Here's the list:

1. Make our starters earlier and bigger. I tend to do most of the yeast management and sometimes those poor little critters only get 24-36 hours of time to warm up and get ready to chew through some sugars. We also only have two 2000mL flasks and one stir plate so they end up splitting time on it. We're going to buy a couple of 4 liter flasks and a second stir plate to really handle the pitches we need for lagers and higher gravity beers.
   
2. Make the same beers until we get them dialed. We've brewed our way through a good number of the recipes in Jamil's Brewing Classic Styles. This has been wonderfully informative on the ways different ingredients play in different styles. But the only beer we've ever scored in the 40's on was the ginger wheat recipe I've brewed over and over and over again through the years. Slowly tweaking the recipe every time has gotten it to the point that it's really balanced, drinkable and has a huge amount of flavor.
   So we're going to make beers we've made before, that we can drink ten gallons of over the course of the summer and not get sick of. And we're going to make them until we get it right.
   
3. Take (even better) notes. I'm a big fan of brewing software. (We use Beer Alchemy. I'm partial to it because it's a well built Mac UI and it's dead simple to use despite having almost all the complexity you could want.) We already take detailed notes and monitor fermentation. But I'm talking about taking it to the next level and having a brewer's log detailed enough to track mash thickness, sparge rates, actual pH vs target pH, mash efficiency, evaporation, target vs actual attenuation, etc.
   There are a lot of little variables which don't lend themselves to tracking easily in the software but can (or at least I think they should) tell us something about the beers that turn out great vs. the ones that don't. (The fact that I'm spending a fair amount of time talking quality assurance with my buddy Gary who is damn close to opening up Panic Brewing just might have something to do with this.

So we'll see if it's made any difference by the end of the summer... It definitely can't hurt.

Original Gravity vs. Plato / Brix

Oddly enough, the homebrew world and the professional brewing world use two totally different units to measure dissolved sugar content in our wort and our finished beer. Homebrewers use Specific Gravity and most pros use Plato. Why you may ask? I don't really know. Probably just 'cuz that's what I started with'.

Both give you a means to measure potential alcohol content and actual attenuation. Both are fairly straightforward to read and to use. So why should anyone care about the difference? Well, they mean different things and have different unit qualities.

Specific gravity (S.G.) is the ratio of the density of a sample liquid (wort) to the density of water. Because wort has dissolved sugars and a few other compounds in it, it's more dense than water. As our little microbial friends do their job and convert that sugar over to alcohol, which happens to be even less dense than water, the SG of the solution drops. There are some well-established formulas / calculators to help you with the exact math, but the scale provides a very simple approximation. Under most normal fermentation conditions, the part after the decimal point is pretty close to what your finished alcohol content will be.

So for a 1.050 SG beer, fermented to 1.012 FG (75% attenuation), you get 5% alcohol. (.05 = .05)

For a 1.080 SG beer, fermented to 1.019 FG (75% attenuation), you get 8.01% alcohol. (.08 ≈ .0801)

One usually measures SG with a hydrometer. It uses a specifically calibrated weight and a scale to measure the relative density of the liquid. Since the pre-fermentation solution has a higher density than plain water and alcohol has a lower density than water, it's straightforward to calculate the finished alcohol percentage. (Technically we lose some CO2 out of the airlock, but it's not enough to matter.)

Brix or Plato is the percentage of dissolved sucrose by weight in a solution. As I mentioned above, technically this is an approximation in wort because not all of the sugars all sucrose and not all of the dissolved solids are fermentable. Regardless, it's a pretty damn good estimate. (Brix and Plato are technically very slightly different scales, but for all practical purposes they can be used interchangeably.)

1 degree brix equals 1 gram of sugar dissolved in 100 grams of water. Also pretty simple, right? So for those same beers we talked about, a 1.050 OG is equivalent to 12.5 plato (or 12.5% dissolved sugar) and a 1.080 OG beer is equivalent to 19.3 plato (or 19.3% dissolved sugar.)

Typically you'd use a refractometer to measure Brix. It uses a known change in the refractive index to measured the percentage of dissolved sugar. However, alcohol's different refractive index makes it basically impossible to use a refractometer to measure finished gravity. It's just not the right tool for that job.